I'm an Al-Qadim fan, and one of my biggest joys is going back and forth through AQ's poster maps. A lot of effort was put into making them the same scale and related to each other.

I've been digging through Dark Sun materials looking for nonweapon proficiencies. Of course that requires some reading of the source material. These sets certainly have some evocative names and interesting settings:
Mind Lords of the Last Sea
Windriders of the Jagged Cliffs
The Ivory Triangle
City by the Silt Sea

Do the maps from these various sets match up into any type of cohesive whole? It's impossible to tell from the .pdfs without printing them out.

None of those mentioned really add new areas, but they do add some new locations such as towns that are not on the revised box set map(s). If you add the revised box set with the map from The Valley of Dust and Fire though you do get a little more (across the sea of silt). Here is a map. http://arena.athas.org/uploads/default/ ... 96aa88.jpg Note that the north-eastern corner is not official, but since it is presumably all silt it shouldn't matter too much.

If you like the expanded Athas idea, http://ds.daegmorgan.net/ is home to the Athas Cartographers Guild. Most of these maps were created in the early 2000's by Stephen Bell, who after a long hiatus, has just recently returned to Athas. There is hope he may start the project up again.